The Boston Red Sox are a little over two weeks into their 2025 campaign, and with the club currently sitting at an 8-9 record, there is a lot to be desired, given the team’s slow start.
Like Boston’s early offensive woes, the Red Sox bullpen has also gotten off to a rocky start, owning a 3.99 ERA, good for 14th in all of MLB. Boston’s bullpen includes a mix of well-established and unproven arms, leaving much room for volatility.
It's still early and everyone's pitched just a small sample size of innings, but here are three relievers who have climbed up the Red Sox trust tree and two who have fallen.
3 relievers who've moved up the Red Sox trust tree
Aroldis Chapman
The left-handed flame thrower, Aroldis Chapman, is the first reliever who has seen his trust stock significantly rise. Chapman, who the Red Sox signed in December, has gotten off to a hot start in 2025. In addition to leading the team in saves with four, he has pitched to a 1.23 ERA and 351 ERA+ and struck out 12 in 7.1 innings of work.
Given his pedestrian 2024 season, which saw him have a 3.79 ERA and a 111 ERA+ in 61.2 innings, and his largely unpopular arrival to the team, Chapman started 2025 around halfway up the tree. However, given his great start, the southpaw has climbed quite a bit, quickly becoming one of the team’s most dependable relievers.
Justin Wilson
Justin Wilson is the second biggest climber on Boston’s trust tree. The 37-year-old, who Boston signed in November, was initially seen as just another lefty option manager Alex Cora could use to eat innings in blowouts. However, Wilson’s strong start has raised his stock; in six innings of work, he has pitched to a 3.00 ERA, a 2.33 FIP, and an ERA+ of 145.
With Wilson owning a 5.59 ERA last season, his numbers in 2025 are a pleasant surprise, giving Cora another option in higher-leverage situations.
Josh Winckowski
The last reliever who saw the biggest boost to his trust stock is Josh Winckowski. Once seen as a trade piece, Winckowski has had a bright start to his 2025 campaign. In 6.2 innings, the right-hander has pitched to a 2.70 ERA and a 160 ERA+, all while scattering four hits.
After a miserable 2024, Winckowski will look to continue his promising performances and return to his prior role as Cora’s best long reliever. Once not even on the tree, Winckowski has climbed quite a bit, hoping to recapture his success from 2023.
2 relievers who've moved down the Red Sox trust tree
Justin Slaten
The first significant faller in Boston’s bullpen is Justin Slaten. After a great season last year, Slaten has faltered to start in 2025. Pitching in six innings, Slaten currently has a 5.14 ERA and an 84 ERA+. He's working his way back up, though, after a stellar one-inning, two-strikeout outing against the Rays.
Zack Kelly
Zack Kelly is the second Red Sox reliever to see a significant blow to his trust status. Kelly, who found success in a productive 2024 season, became a dependable option at Cora’s disposal. However, Kelly has hit a brick wall in 2025, holding a 6.30 ERA and 68 ERA+ in 10 innings.
Hopefully, for the Red Sox, Kelly and Slaten will eventually find their footing in 2025. Given their past performances, both relievers have proven to be dependable arms.